JP3611425B2 - microwave - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microwave oven including a radio wave leakage prevention member and a weight sensor below a bottom portion of a heating chamber.
[0002]
[Problems to be solved by the invention]
An example of a conventional configuration of this type of microwave oven is shown in FIGS.
A shaft through hole 3 is formed at the center of the bottom plate portion 2a that forms the bottom of the heating chamber 1. The bottom plate portion 2a is screwed to the flange portion of the side plate portion 2b constituting the side portion of the heating chamber 1 together with the support plate 4 disposed below the bottom plate portion 2a. A cylindrical cylindrical portion 5 surrounding the shaft through hole 3 is fixed to the lower surface of the bottom plate portion 2a by welding, and three fixtures 6 having mounting holes 6a around the cylindrical portion 5. Is fixed by welding. Between the bottom plate portion 2a and the support plate 4, a lower surface heater 7 made of a planar heater is disposed.
[0003]
On the lower surface side of the support plate 4, a mounting plate 10 having a plate member 8 having a plurality of plate-like spring portions 8 a and a weight sensor 9 is screwed into the mounting hole 6 a of the mounting tool 6. It is fixed by. In this state, the spring portion 8a is in pressure contact with the cylindrical portion 5 and the mounting plate 10 while being sandwiched between them. The shaft 12 protruding upward from the weight sensor 9 passes through the cylindrical portion 5 and the shaft through hole 3 and protrudes into the heating chamber 1.
[0004]
In this case, when the radio wave leakage preventing member 13 is configured by the cylindrical portion 5 and the spring portion 8a, and the microwave (radio wave) supplied into the heating chamber 1 during cooking in the range leaks to the shaft through hole 3 side, The microwave is attenuated by the radio wave leakage preventing member 13 to prevent the microwave from leaking to the outside.
[0005]
However, the conventional configuration described above has the following drawbacks.
First, since the cylindrical portion 5 and the fixture 6 of the radio wave leakage prevention member 13 are fixed to the lower surface of the bottom plate portion 2a of the heating chamber 1 by welding, the material used for the bottom plate portion 2a is limited. It is not possible to use pre-painted pre-coated materials. If pre-coating material is to be used, it is necessary to mask the part to be welded at the time of painting. In this case, the unpainted part (metal surface) comes out to the inside of the heating chamber. , It will make it look bad. In addition, the number of welding processes is increased, and the cost is increased accordingly.
[0006]
The weight sensor 9 is close to the lower surface heater 7 that is a heat source and is easily affected by the heat of the lower surface heater 7 , so that a high heat resistance is necessary and expensive. In addition, the weight sensor 9 is adversely affected by the heat of the lower surface heater 7 , and accurate weight detection cannot be performed, which may result in poor cooking performance. Furthermore, since the radio wave leakage prevention member 13 is divided into two members, the cylindrical portion 5 and the spring portion 8a, it is necessary to combine them at the time of assembly, and workability is poor.
[0007]
The present invention has been made in view of the above-described circumstances, and its purpose is to eliminate the need for welding to the bottom of the heating chamber, to make the weight sensor less susceptible to the heat of the lower surface heater, An object of the present invention is to provide a microwave oven that can improve workability during assembly.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a heating chamber having a shaft through hole formed in the bottom, a lower surface heater provided at the bottom of the heating chamber, and the bottom below the bottom of the heating chamber. A mounting plate that is disposed in a state in which a space is formed between the side plate and the side portion is fixed only on the side portion of the heating chamber, and a shaft that is attached to the lower surface side of the mounting plate and is inserted through the shaft through hole. A weight sensor that detects the weight of the object to be cooked, and a cylinder portion that is attached to the upper surface side of the attachment plate, and the attachment plate is fixed below the bottom of the heating chamber so that the cylinder portion is The electromagnetic wave leakage prevention member is provided that is elastically and electrically contacted without being welded to the lower surface of the bottom of the heating chamber so as to surround the shaft through hole.
[0009]
According to the above configuration, the mounting plate to which the weight sensor is attached is fixed at the side of the heating chamber, and the radio wave leakage prevention member is attached to the mounting plate. Therefore, it is necessary to weld the bottom of the heating chamber. Absent. In addition, a space is formed between the mounting plate to which the weight sensor is attached and the bottom of the heating chamber, and the weight sensor can be moved away from the lower surface heater provided at the bottom of the heating chamber. Is less susceptible to the heat of the bottom heater. Furthermore, since the radio wave leakage prevention member is attached to the mounting plate, the radio wave leakage prevention member and the mounting plate can be easily attached. Further, the radio wave leakage prevention member attached to the mounting plate elastically contacts the lower surface of the heating chamber bottom, so that it can be reliably brought into contact with the heating chamber bottom, and radio wave leakage can be prevented more reliably. .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
First, in FIG. 1, the heating chamber 21 is formed in a rectangular shape from left and right side plate portions 22, a bottom plate portion 23, a ceiling plate portion (not shown), and a rear plate portion. A flange portion 24 projecting sideways is formed integrally with the lower end portion of the both side plate portions 22. A shaft through hole 25 is formed substantially at the center of the bottom plate portion 23 constituting the bottom of the heating chamber 21, and a recess 26 is formed so that the peripheral portion of the shaft through hole 25 is recessed upward. Has been. On the lower surface of the bottom plate portion 23, a lower surface heater 27 made of a planar heater is disposed.
[0011]
As shown in FIG. 2, the attachment plate 29 to which the weight sensor 28 is attached is elongated in the left-right direction, and has flange portions 31 that protrude from the left and right sides via the rising piece portions 30. doing. The mounting plate 29 is a screw formed on the flange portion 31 with the left and right side portions of the bottom plate portion 23 being sandwiched between the flange portion 24 and the flange portion 31 formed on the left and right side plate portions 22. The screw 32 that has passed through the insertion hole 31 a and the screw insertion hole formed in the bottom plate portion 23 is screwed into the mounting hole 24 a formed in the flange portion 24, thereby being fixed to the side plate portion 22 together with the bottom plate portion 23. Therefore, the left and right side portions of the mounting plate 29 are fixed at the side portion of the heating chamber 21 in a state where the space portion 33 is formed between the mounting plate 29 and the bottom plate portion 23 below the bottom plate portion 23.
[0012]
The weight sensor 28 is of the electrostatic capacity type, and as shown in FIG. 4, a movable member 36 that can be displaced in the vertical direction together with the shaft 35, a wiring board 37 provided with a detection circuit, and a movable member 36. A sensor plate 38 and the like are provided. An upper end portion of the shaft 35 penetrates the shaft through hole 25 and protrudes into the heating chamber 21, and a turntable (not shown) accommodated in the heating chamber 21 is connected to the shaft 35. ing. The weight sensor 28 is configured such that the sensor plate 38 is deformed via the movable member 36 due to the load applied to the shaft 35, and the capacitance changes with the deformation of the sensor plate 38. Based on detection of a change signal by a control device (not shown), the weight of the object to be cooked accommodated in the heating chamber 21 is detected.
[0013]
The movable member 36 is provided with a gear 39, and this gear 39 meshes with a gear 41 that is rotated by a turntable driving motor 40. When the motor 40 rotates, the turntable is rotated via the gears 41 and 39 and the shaft 35.
[0014]
A radio wave leakage prevention member 42 is disposed between the mounting plate 29 and the bottom plate portion 23. As shown in FIG. 3, the radio wave leakage prevention member 42 is integrated with a cylindrical portion 44 having a flange portion 43 at the upper end portion and a lower portion of the cylindrical portion 44 by, for example, caulking. It is composed of a spring member 46 having a plate-like spring portion 45, and is mounted on the mounting plate 29 by fixing the spring portion 45 portion by a fixing member 48 fixed to the upper surface of the mounting plate 29 by screws 47. ing.
[0015]
The radio wave leakage prevention member 42 is attached to the attachment plate 29, and the cylindrical portion 44 surrounds the shaft 35. Further, the radio wave leakage prevention member 42 has a height dimension H1 (see FIG. 3) in a free state attached to the attachment plate 29, and is a dimension between the upper surface of the attachment plate 29 and the lower surface of the recess 26 in the bottom plate portion 23. It is set to be larger than H2 (see FIG. 1), and the spring portion 45 is elastically in contact with the upper surface of the mounting plate 29 in a state where the mounting plate 29 is mounted to the lower portion of the heating chamber 21. At the same time, the flange portion 43 of the cylindrical portion 44 is in elastic contact with the lower surface of the recess 26 in a state surrounding the shaft through hole 25. In this case, the spring portion 45 is also in contact with the fixing member 48.
[0016]
According to the above embodiment, the following effects can be obtained.
Since the attachment plate 29 to which the weight sensor 28 is attached is fixed at the side of the heating chamber 21 and the radio wave leakage prevention member 42 is attached to the attachment plate 29, the bottom plate portion 23 constituting the bottom of the heating chamber 21. There is no need to weld to. For this reason, it becomes possible to use a precoat material for the bottom plate part 23, and the selection range of the material used becomes wide. Further, the unpainted portion is not exposed on the bottom plate portion 23, the appearance is not deteriorated, and further, the number of welding steps is not required, and the cost can be reduced correspondingly.
[0017]
Since the radio wave leakage prevention member 42 has a configuration in which the cylindrical portion 44 and the spring member 46 are integrated and have elasticity, for example, a member constituting the heating chamber 21, the radio wave leakage prevention member 42, the mounting plate 29, and the like. Even if it is affected by heat, it always comes into contact with the bottom plate portion 23, the mounting plate 29, and the fixing member 48 reliably, and radio wave leakage can be prevented more reliably. In this case, since the mounting plate 29 to which the radio wave leakage prevention member 42 is attached is fixed at the side of the heating chamber 21, the radio wave leakage prevention member 42 tends to be separated from the bottom plate portion 23. The member 42 has elasticity, and the height dimension H1 in the free state of the radio wave leakage prevention member 42 is set to be larger than the dimension H2 between the attachment plate 29 and the bottom surface of the recess 26 in the bottom plate portion 23. Therefore, the radio wave leakage prevention member 42 can be reliably brought into contact with the bottom plate portion 23.
[0018]
A space 33 is formed between the mounting plate 29 to which the weight sensor 28 is attached and the bottom plate portion 23 of the heating chamber 21, and the weight sensor 28 is moved away from the lower surface heater 27 provided on the bottom plate portion 23. Therefore, the weight sensor 28 is hardly affected by the heat of the lower surface heater 27. For this reason, as the weight sensor 28 and the motor 40, those having low heat resistance can be used, and inexpensive parts can be used. In addition, since the weight sensor 28 is hardly affected by the heat of the lower surface heater 27, it becomes possible to detect the weight as accurately as possible and to prevent the cooking condition from being deteriorated.
[0019]
Furthermore, since the radio wave leakage prevention member 42 is attached to the attachment plate 29 via the fixing member 48, the radio wave leakage prevention member 42 and the attachment plate 48 can be easily attached. Further, since the radio wave leakage preventing member 42 is configured to elastically contact the lower surface of the bottom plate portion 23 of the heating chamber 21, it can be reliably brought into contact with the bottom portion of the heating chamber 21. In addition, since the flange portion 43 is provided on the cylindrical portion 44 of the radio wave leakage preventing member 42 and the flange portion 43 is in contact with the lower surface of the bottom plate portion 23, a large contact area with the bottom plate portion 23 can be secured. It becomes possible to prevent radio wave leakage more reliably.
[0020]
【The invention's effect】
According to the present invention, the following effects can be obtained.
According to the microwave oven of the first aspect, the mounting plate to which the weight sensor is attached is fixed at the side of the heating chamber, and the radio wave leakage prevention member is attached to the mounting plate. There is no need to do. In addition, a space is formed between the mounting plate to which the weight sensor is attached and the bottom of the heating chamber, and the weight sensor can be moved away from the lower surface heater provided at the bottom of the heating chamber. The sensor is less susceptible to the heat of the bottom heater. Furthermore, since the radio wave leakage prevention member is attached to the mounting plate, the radio wave leakage prevention member and the mounting plate can be easily attached. In addition, the radio wave leakage preventing member attached to the mounting plate elastically contacts the lower surface of the bottom of the heating chamber, so that it can be reliably brought into contact with the bottom of the heating chamber.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view of an essential part showing an embodiment of the present invention. FIG. 2 is a perspective view of a state in which a radio wave leakage prevention member is attached to a mounting plate. FIG. 4 is a longitudinal side view of the weight sensor portion. FIG. 5 is a view corresponding to FIG. 1 showing the conventional configuration. FIG. 6 is an exploded perspective view of the bottom plate portion and the plate member.
21 is a heating chamber, 22 is a side plate, 23 is a bottom plate (bottom), 24 is a flange, 25 is a shaft through hole, 27 is a bottom heater, 28 is a weight sensor, 29 is a mounting plate, 31 is a flange, 33 Is a space part, 35 is a shaft, 40 is a motor, 42 is a radio wave leakage prevention member, 44 is a cylinder part, 45 is a spring part, and 48 is a fixing member.

Claims (1)

A heating chamber having a shaft through hole formed at the bottom;
A lower surface heater provided at the bottom of the heating chamber;
A mounting plate disposed in a state of forming a space between the bottom and the bottom of the heating chamber, the side being fixed only at the side of the heating chamber;
A weight sensor that is attached to the lower surface side of the mounting plate and detects the weight of the object to be cooked via a shaft inserted through the shaft through hole,
A bottom surface of the heating chamber bottom in a state where the cylindrical portion surrounds the shaft through-hole by attaching the mounting plate to the upper surface side of the mounting plate and fixing the mounting plate below the bottom of the heating chamber. A microwave oven comprising: a radio wave leakage preventing member that is elastically and electrically contacted without being welded .

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